Research is proposed to isolate and define new antitumor and antibiotic compounds from marine microorganisms. A collaborative program has been established between the Institute of Marine Sciences at the University of North Carolina and the Scripps Institution of Oceanography at the University of California, San Diego. The collaboration would provide the multidisciplinary expertise in marine microbiology and natural products chemistry which is viewed as essential for the effective development of this new area of investigation. The research proposed is formulated as an NIH Consortium Grant, and consists of the following specific goals: --The development of a research program to address the ecology and physiology of marine microorganisms, with the specific goal being to generate greater knowledge of and confidence in the isolation and culture of "true" marine microorganisms. --The establishment of a large culture collection (approximately 3,000-4,000 species) of obligate marine microorganisms which include all major classes of bacteria (Scripps Institution) and fungi (Univ. of North Carolina). --The development of an interactive pharmacological testing program in the area of antitumor-antibiotics. Antitumor and antibiotic assays would be performed at SIO (antibiotic), and through collaborations with the National Cancer Institute and the pharmaceutical industry (antitumor). Particular attention would be focused upon marine microorganisms which produce potent inhibitors of tumor cell division. --The isolation and structure determination of new antitumor-antibiotics from the culture broths of marine microorganisms. It is estimated that between 10-20 broths could be chemically investigated per year with the personnel requested.